Suitable Lab Host Plants: Any Arabis or Brassica species including Brassica nigra; Isatis tinctoria; andCardaria drabaSpring white larvae are generalists and can accept many species of mustards in the lab. Avoid Descurainia sophia.

How to Find Eggs:Isolated Host Plants; Look on lower half of plant; Female spring whites use many mustards both as a nectar source as well as a larval host plant. Unlike orangetip females, spring white females will lay several eggs towards the bottom 1/3 of its host; both on leaves as well as stems. It's not uncommon to see a female nectaring on Arabis, and then fly towards the bottom of the host plant to lay eggs. Eggs are greenish; turning orange after 24 hours. Eggs can sometimes be very easy to find if timing in the spring is correct. Once ova hatch; first instar larvae will crawl towards the inflorescens to initiate feeding on flowers and fruits. First instar larvae are cannibalistic and will feed on any ova it finds.

How to Find Caterpillars in the Field: It is abundantly easier to find eggs and/or to get eggs out of live females. But, to find late instar larvae, (many will have been taken out by predation) look for Caterpillar Strip Patterns.

Field Notes: The easiest way to raise spring whites is to either find multiple eggs towards the base of host Arabis and Descurainia pinnata. However, in the mountain ranges of Nevada, Utah, and Colorado, spring white caterpillars oftentimes are the more common caterpillar found on these mustards as compared to sara orangetips, desert marbles, and large marbles. Note: If you are rearing spring whites, sara orangetips, desert marbles, and/or large marbles for scientific purposes and are using Arabis spp. for lab rearing, always keep good notes of collection localities, as well as when and where you are collecting cuttings of plant because, many times, when you harvest cuttings of Arabis, you unintentionally will be harvesting more immatures of spring white eggs and caterpillars.

For most, that is great, unless you happen to live on a boundary between two subspecies of spring whites. This is applicable to Northern Utah where Pontia sisymbri nigravenosa flies in the Basin and Range Province whereas Pontia sisymbri Northern Utah segregate flies in Wasatch Range. Those two ranges border each other in Utah and Salt Lake Counties.

Finding late instar caterpillars is not too difficult in the field; but, oftentimes these larvae can be parasitized.